There are known superconducting bearings that have a second bearing ring to which a second body made of a type-2 superconducting material is attached. Flux tubes, so-called vortices, with a superconducting current flowing around them, develop in the type-2 superconducting material of the second body in the presence of a magnetic field. The vortices can be displaced in relation to this exciting magnetic field only against a mechanical resistance, so that the magnetic field together with the type-2 superconducting material of the second body forms a self-adjusting bearing on the second bearing ring.
It is known from practice that a magnetic field which excites flux tubes is supplied by permanent magnets, by normally conducting coils or by superconducting coils arranged on a first bearing ring of the bearing. One disadvantage is that both the coils and the permanent magnets are able to supply magnetic fields of only a small size, for example in comparison with the critical magnetic field of the material of the type-2 superconductor of the second body beneath the type-2 superconductor of the second body at temperatures below the transition temperature. The high restoring forces and/or holding forces of the superconducting bearing, which are possible in principle, are achieved only partially because of the comparatively low magnetic field.
German Patent Application No. 10 2009 009 126.2, filed on Feb. 17, 2009, describes a superconducting bearing, which includes a first body on a first bearing ring and a second bearing ring with a second body, such that the two bodies are made of type-2 superconducting material, and an external magnetic field is permanently applied to the first body at the first bearing ring, such that the second body is assembled on the second bearing ring in such a way that the magnetic field applied to the first body extends at least partially into the area of the second body. The distribution of the flux tubes in the second body is determined by the magnetic field applied to the first body, the structure of which may in turn be adjusted by an external magnetic field. With regard to performing the assembly of the superconducting bearing, it is provided that first the outer magnetic field is applied to the first body at the first bearing ring and then the two bearing rings are assembled, so that the magnetic field applied to the first body at least partially permeates the second body. Since the first bearing ring has the first body with the applied magnetic field, when the second bearing ring is assembled, the assembly of the bearing may prove to be complex on the whole. Since a superconductor does not receive the external magnetic field completely, but instead it does so with only minor flux density losses, the flux density losses may be added up in assembly because the flux density losses occur twice in performing this method, namely in magnetization through the external magnetic field and then in magnetization of the second body in the magnetic field of the first body. The bearing assembled by this method then has a magnetic field volume density lower than that theoretically possible, thus, also reducing the holding forces and the stiffness of the assembled bearing.